Ib-M6 Antimicrobial Peptide: Antibacterial Activity against Clinical Isolates of Escherichia coli and Molecular Docking.

The Ib-M6 peptide has antibacterial activity against non-pathogenic Escherichia coli K-12 strain. The first part of this study determines the antibacterial activity of Ib-M6 against fourteen pathogenic strains of E. coli O157:H7. Susceptibility assay showed that Ib-M6 had values of Minimum Inhibitory Concentration (MIC) lower than streptomycin, used as a reference antibiotic. Moreover, to predict the possible interaction between Ib-M6 and outer membrane components of E. coli, we used molecular docking simulations where FhuA protein and its complex with Lipopolysaccharide (LPS-FhuA) were used as targets of the peptide. FhuA/Ib-M6 complexes had energy values between -39.5 and -40.5 Rosetta Energy Units (REU) and only one hydrogen bond. In contrast, complexes between LPS-FhuA and Ib-M6 displayed energy values between -25.6 and -40.6 REU, and the presence of five possible hydrogen bonds. Hence, the antimicrobial activity of Ib-M6 peptide shown in the experimental assays could be caused by its interaction with the outer membrane of E. coli.

Changes in Left Ventricular Mechanics After Sleeve Gastrectomy.

OBJECTIVE: The aim of this study was to examine echocardiographic parameters of left ventricle (LV) mechanics in obese patients before and after sleeve gastrectomy (SG). DESIGN AND METHODS: Twenty-five obese individuals submitted to laparoscopic SG were enrolled in this study. Echocardiography was performed before and after the procedure, and left ventricle mechanics were evaluated by speckle tracking imaging. RESULTS: Before surgery, altered global longitudinal strain (GLS) values were present in 56% of the patients. In a mean follow-up of 3.6 ± 0.5 months after surgery, there was an increase in GLS values (from 17.4 ± 3.2 to 19.3 ± 2.7%, P = 0.01). There was an inverse correlation between the absolute values of GLS in the preoperative period and the variation in the GLS at follow-up (r = 0.577, P = 0.002). Measurements of global circumferential strain (GCS), global radial strain (GRS), and LV twist were normal preoperatively and did not change after surgery. CONCLUSIONS: Altered global longitudinal strain values were common in young obese patients. Sleeve gastrectomy increased global longitudinal strain even in the early postoperative phase without promoting changes in global radial strain, global circumferential strain, and left ventricle twist measurements.

Biopolymeric pellets of polyvinyl alcohol and alginate for the encapsulation of Ib-M6 peptide and its antimicrobial activity against E. coli.

The encapsulation of Ib-M6 antibacterial peptide in pellets of polyvinyl alcohol (PVA) and polyvinyl alcohol-alginate (PVA-Alg) matrices was carried out in order to explore its controlled release and activity against Escherichia coli K-12. The pellets were obtained by combined ice segregation induced self-assembly (ISISA) and freezing-thawing methods and their microstructure was studied by scanning electron microscopy. Bromothymol blue was used as a model compound to study the transport mechanisms and release from pellets. The results show that there is a significant effect of the total concentration of PVA precursor solutions, the mass ratio of PVA of different molecular weights and the addition of alginate on the microstructure and transport properties of pellets. The antibacterial activity of Ib-M6 against Escherichia coli K-12 was not affected by the encapsulation in PVA pellets. However, the release of Ib-M6 from PVA-Alg pellets was not possible, probably due to the electrostatic interaction of positively charged Ib-M6 and negatively alginate structure. Nonetheless, the controlled release of Ib-M6 from polymeric matrices can be fitting by modifying parameters such as the concentration and type of polymer precursors.

Preparation of extruded polyethylene/chitosan blends compatibilized with polyethylene-graft-maleic anhydride.

Novel films of polyethylene and chitosan were obtained using extrusion. These polymers have interesting properties, and processing them with methods that are of high use in the industry, such as the extrusion method, can have a significant effect on the potential applications of these materials. The individual materials were thermally characterized; after this, extruded films of low density polyethylene and chitosan mixtures were prepared with the addition of polyethylene-graft-maleic anhydride as a compatibilizer for the blends, and glycerol, as a plasticizer for chitosan. The use of compatibilizer and plasticizer agents improved the processability and compatibility of the mixtures, as well as their mechanical properties, as revealed by mechanical property measurements and scanning electron microscopy. It was possible to prepare blends with a maximum chitosan content of 20 wt%. The material stiffness increased with the increase of chitosan in the sample. FTIR studies revealed the existence of an interaction between the compatibilizer and chitosan.

Long-term follow-up of pregnant women after percutaneous mitral valvuloplasty.

The aim of this study was to evaluate long-term clinical follow-up and echocardiographic data on pregnant patients with mitral stenosis who underwent percutaneous mitral valvuloplasty (PMV) in our center and the development of their infants. PMV has proven to be an effective alternative to treat pregnant patients with mitral stenosis. However, long-term outcome of these patients, as well as the potential harmful effects caused by radiation on their infants, still awaits to be determined. From January 1988 to February 1999, 30 pregnant women (mean gestational duration, 24.95 +/- 5.59 weeks) underwent PMV. Twenty-three (77%) were subsequently followed by a medical interview during 5.33 +/- 3.12 years. Clinical variables such as NYHA functional class (FC), the need of a repeat PMV or surgical procedure, the presence of embolic events, and mortality rate were evaluated during follow-up. Mitral valve area, mean transmitral gradient, and the presence of mitral regurgitation were also assessed by Doppler echocardiography. Clinical data on the development of the infants were obtained from the assistant pediatricians. All patients were in NYHA FC III or IV before the procedure. During follow-up, 91% of them were in FC I and II. Two patients (9%) who had remained in FC III underwent a repeat successful PMV; no further surgery was required. There were no embolic events or death related to the procedure. Echocardiography showed an initial increase in mitral valve area from 1.14 +/- 0.22 cm(2) to 2.01 +/- 0.21 cm+/- (P < 0.0001). During long-term follow-up, it decreased to a mean of 1.75 +/- 0.24 cm(2) (P < 0. 0001). Initial transmitral valve gradient decreased from 17.73 +/- 4. 56 mm Hg to 5.91 +/- 1.80 mm Hg (P = 0.0001) and 8.95 +/- 3.58 (P = 0.002) during long-term follow-up. Twenty one children (96%), aged 4. 91 +/- 2.8 years, showed normal growth and development, and no clinical abnormalities were observed. These favorable long-term results suggests PVM to be the procedure of choice to treat pregnant women with mitral stenosis who remain in FC III or IV despite adequate medical therapy. No harmful effects due to the use of radiation were observed in the children.

[Echocardiographic relation criteria. A new selection method for mitral valvotomy with balloon catheter]. / Critério de relação ecocardiográfica. Um novo método para a indicação da valvotomia mitral com cateter-balão.

PURPOSE: To find out new subjects that could be useful to select patients between 9 and 12 points, according to Block's Criteria, to mitral balloon valvotomy. METHODS: One hundred and forty patients underwent mitral balloon valvotomy. Among them, 29 (21%) had between 9 and 12 points. These patients were divided into two groups: group A-patients with mitral valve area > or = 1.5cm2, immediately after balloon valvotomy and in the follow-up period; group B-patients with mitral valve area < 1.5cm2 immediately after or during the follow-up period, patients with severe mitral regurgitation after the procedure and patients who died in the follow-up period. All patients were analyzed by echocardiographic relation criteria (ERC): calcification + subvalvar disease/thickness + mobility. Each one was quantified from 1 to 4 points according to the degree of valvular disease. RESULTS: Group A was composed of 17 (51%) and group B 12 (41%) patients. The variables age, sex, previous mitral commissurotomy and atrial fibrillation did not show difference between groups. In group A mitral valve area (cm2) increased from 1.15 +/- 0.25 to 1.97 +/- 0.26 (p < 0.00001) keeping stable during the follow-up period. In group B percutaneous mitral balloon valvotomy resulted in an increase from 1.26 +/- 0.19 to 1.77 +/- 0.16 (p < 0.00001), however, there was an important decrease in the follow-up period to 1.34 +/- 0.15 (p < 0.00001). The ERC showed that all group A patients had a relation < 1. However, in group B, 10 patients (83%), the relation was > or = 1, and in only 2 patients (17%) was < 1 (p < 0.00001). CONCLUSION: The group of patients between 9 and 12 points in the Block's criteria is heterogenic, therefore, each case might be evaluated individually and the echocardiographic relation criteria should be used in order to select these patients to the procedure.

Echocardiographic long-term evaluation of percutaneous balloon mitral valvotomy.

Percutaneous balloon mitral valvotomy (BMV) is an alternative therapeutic method for patients with mitral stenosis. We studied 62 patients (56 females, mean age 36.4 years) who underwent balloon mitral valvotomy. Five patients were pregnant and in New York Heart Association Functional Class IV. Doppler echocardiographic studies were performed prior to the procedure, and at 7 days, 6 months, 12 months, and 24 months after the procedure. We studied the following parameters: echo-score by the sum of valvular mobility, thickening, and calcification, and subvalvular disease, graded from 1 to 4; and mitral valve area (MVA) and mitral pressure gradient (MPG) by Doppler echocardiography. The patients were separated into two groups: group I with an echo-score less than or equal to 8 (40 patients), and group II with an echo-score greater than or equal to 9 (22 patients). Mitral valve area and MPG were compared with hemodynamics through the correlation coefficient and linear regression. Comparison between groups I and II was performed using the unpaired Student's t-test. Follow-up of MVA and MPG was analyzed by analysis of variance. The Student's t-test did not show any significant difference between MVA and MPG before balloon mitral valvotomy. There was significant decrease of MVA in group II (P less than 0.01) in the last three studies. There was significant increase in MPG in group II (P less than 0.01) in every postvalvotomy study. The analysis of variance of group I showed statistical increase of the MVA, and significant decrease of the MPG after BMV. The analysis of variance of group II showed significant increase in MVA and significant decrease in MPG between the pre- and the first postvalvotomy study. There was significant decrease (P less than 0.01) in MVA, and increase in MPG in the three postvalvotomy studies. Complications included mitral regurgitation, residual interatrial communication, pericardial effusion due to an atrial wall perforation, and peripheral embolization. Atrial fibrillation did not significantly alter the results of BMV. Results were considered positive when MVA was greater than 1.5 cm 2 and area increase was greater than 25%. Patients with an echo-score less than or equal to 8 (group I) benefit from BMV, with a positive predictive value greater than 78%. In pregnant patients the symptomatology was alleviated by BMV, without any signs of fetal compromise.

[Doppler echocardiographic evaluation of heart transplantation]. / Avaliação ecodopplercardiográfica do transplante cardíaco.

In order to evaluate major Doppler-Echocardiographic parameters for the diagnosis of acute cardiac allograft rejection episodes a serial of 54 Doppler Echocardiograms were performed simultaneously with endomyocardial biopsy in five patients (mean age = 40.2 y/o). Measurements included: right and left chambers diameters, left ventricular (LV) myocardial diastolic thickness, LV systolic function parameters, LV mass, LV volume/mass ratio, LV isovolumic relaxation time, mitral flow peak velocities and pressure half-time. Episodes with acute rejection histopathologic findings, Billingham class III or IV, were associated to increase in LV free wall thickness and LV mass (p less than 0,005) as well as decreased isovolumic relaxation time and pressure half-time (p less than 0,001). Left ventricular systolic function parameters and heart rate were no different comparing rejection and no rejection episodes. However, in each patient, progressive lower values of LV ejection fraction were associated to higher incidence of acute rejection episodes. Isovolumic relaxation time increased promptly following immunosuppressive therapy. Thus, Doppler Echocardiography is a reliable method for early detection of acute cardiac allograft rejection and monitoring of the cardiac transplant recipient.

Insuficiencia coronaria. Evidencias indiretas. / Coronary insufficiency: indirect evidences

O autor analisa a ecocardiografia uni e bidimensional e sua contribuicao para o diagnostico diferencial dos pacientes com dor precordial, principalmente atipica.Enfatisa o conhecimento das manifestacoes indiretas para a avaliacao da insuficiencia coronaria, principalmente o estudo da funcao ventricular esquerda

Importância da ecocardiografia bidimensional na detecçäo e avaliaçäo dos derrames pericárdicos / The importance of two-dimensional echocardiography in the detection and evaluation of pericardial effusion

Os derrames pericárdicos, principalmente septados, podem apresentar sérias dificuldades para sua detecçäo e quantificaçäo pela ecocardiografia convencional. A ecocardiografia bidimensional, em auxílio a modalidade M, permite a detecçäo mais correta dos derrames generalizados, pela regiäo apical e subxifóide. Foram estudados 22 pacientes portadores de derrame pericárdico, dos quais quatro eram septados e oito eram pós-operatórios. Estabeleceram-se as diferenças ecocardiográficas entre os diversos tipos e, em 10 casos, relacionou-se com o aspecto radiológico e com o volume de líquido extraído pela punçäo pericárdica ou pela pericariotomia, mostrando uma razoável correlaçäo (r = 0,76). Conclui-se que a ecocarddiografia bidimensional permite a detecçäo de derrames pericárdicos, especialmente os septados situados fora do alcance do sistema convencional, assim como a sua quantificaçäo, com boa confiabilidade